My teacher says it is not possible to physically
touch molecules, but isn't that what friction is?
Moving molecules quickly so it makes heat?

Question Date: 2006-04-10

Answer 1:

Depending on what you mean by a "molecule" you may
be able to touch a "molecule". When you touch,
for example, your desk, the molecules in your
finger are "in contact" with the molecules of the
desk. What are really in "contact" are the
electrons in your finger with the electrons of the
desk. Electrons, along with the protons and
neutrons, make up atoms. Protons and neutrons are
confined to the core of the atom. More than one
atom combined make up a molecule. The part of the
molecule you are actually "touching" is the
electrons, which are NOT confined to the nucleus
(core). Do these electrons actually touch? The
answer is, not really. When the electrons in your
hand get VERY CLOSE to the electrons in the desk,
they strongly repel each other. This is the force
pushing back on your hand!

Friction is
force based on interactions of the electrons
moving past one another, and also microscopic
roughness. Although two glass slides make appear
to be smooth, there is still a friction force when
they slide over one another. This is due to
little bumps on both surfaces pushing against each
other (their electrons are repelling one another).